video: backlight: Parse PWM polarity cell
This patch enables the reading of the polarity cell from a PWM
phandle and calls pwm_set_invert().
Not all platforms have polarity cell, so skip if it's not pressent.
Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/pwm_backlight.c b/drivers/video/pwm_backlight.c
index bd733f5..a587977 100644
--- a/drivers/video/pwm_backlight.c
+++ b/drivers/video/pwm_backlight.c
@@ -39,6 +39,12 @@
struct udevice *pwm;
uint channel;
uint period_ns;
+ /*
+ * the polarity of one PWM
+ * 0: normal polarity
+ * 1: inverted polarity
+ */
+ bool polarity;
u32 *levels;
int num_levels;
uint default_level;
@@ -57,7 +63,10 @@
(priv->max_level - priv->min_level + 1);
ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
duty_cycle);
+ if (ret)
+ return log_ret(ret);
+ ret = pwm_set_invert(priv->pwm, priv->channel, priv->polarity);
return log_ret(ret);
}
@@ -202,6 +211,8 @@
return log_msg_ret("Not enough arguments to pwm\n", -EINVAL);
priv->channel = args.args[0];
priv->period_ns = args.args[1];
+ if (args.args_count > 2)
+ priv->polarity = args.args[2];
index = dev_read_u32_default(dev, "default-brightness-level", 255);
cell = dev_read_prop(dev, "brightness-levels", &len);